.onoff{
	display:inline-block;
	height:1em;
	width:2.31em;
	font-size:24px;
	background: center center no-repeat;
	background-size:100% 100%; 
	cursor:pointer;
	vertical-align: middle;
}
.onoff.on{
	background-image:url('../image/on.png');
}
.onoff.off{
	background-image:url('../image/off.png');
}